Astronomers See Double: the Gemini South Telescope

A giant telescope with a whopping 8-metre diameter light collecting mirror
opened its Cyclops eye on the Universe today [18 January]. Perched on the
desolate summit of Cerro Pachon in the Chilean Andes at a height of 2737
metres [8,895 feet] the Gemini South telescope is an identical twin of
Gemini North in Hawaii. The two telescopes, located each side of the
equator, will enable UK astronomers to see double - and view the entire sky
in both northern and southern hemispheres.

The Gemini telescopes, in which the UK has almost a quarter share through
the Particle Physics and Astronomy Research Council [PPARC], have been
designed to produce extremely sharp images of the Universe in the infrared
waveband. Viewing in the infrared enables astronomers to see through the
cosmic dust that obscures star forming regions and violent galaxies to
reveal the inner secrets of stellar birth and the deep mysteries of the
Universe. Each telescope also has an optical capability with 10 times the
light gathering power of the Hubble Space Telescope. Coupled with high
technology 'adaptive optics' instruments which will 'take the twinkling out
of stars' the Gemini telescopes will produce images as sharp as those from
space.

Commenting on the dedication of Gemini South, Prof. Ian Halliday, PPARC
Chief Executive, said," This is a significant day for the Gemini telescopes
and for the entire UK astronomy community. Britain is the second largest
partner in the 7-country Gemini consortium. By taking a leading role in such
international projects PPARC ensures that UK scientists have access to
world-class facilities, enabling them to participate at the frontier of
global astronomy research and discovery".

The UK has played a leading role in the design and construction of both
telescopes and many of the scientific instruments on them, and several key
individuals in the international consortium are British including the
overall Gemini Project Director, Dr. Matt Mountain, formerly of the Royal
Observatory Edinburgh.

'About a month ago we reached a milestone when both Gemini North and Gemini
South made observations at the same time but in different parts of the sky
invisible to each other,' said Dr Mountain. 'Today's dedication celebrates a
decade of work by hundreds of people to build these two telescopes that have
now become one observatory'.

UK astronomers have already begun to sample the new capabilities. Dr.
Patrick Roche, [ UK Gemini Project Scientist at Oxford University],
commented,' My colleague Dr Philip Lucas [University of Hertfordshire] and I
have been fortunate to receive some of the early infrared images of star
fields in Orion, which reach deeper than any other previous observations of
the region and reveal many new and interesting structures in unprecedented
detail. These and other data demonstrate that both Gemini telescopes meet
their design requirements, delivering high sensitivity and exquisite image
quality. We now look forward to a long and productive phase of scientific
exploration'.

A further taster of discoveries to come from Gemini South was recently seen
from its twin on Hawaii when it achieved a spectacular image dubbed 'the
perfect spiral galaxy' using an instrument called GMOS [Gemini Multi-Object
Spectrograph]. The dramatic image clearly demonstrated the power of Gemini's
massive 8-metre light gathering mirror coupled with the 24 million
ultra-sensitive pixel array of GMOS to capture beautiful astronomical
phenomena. The UK's Astronomy Technology Centre [ATC], Durham University,
and Canadian colleagues built the GMOS instrument.

'GMOS is one of the most significant scientific instruments ever built by
the ATC,' said Dr Adrian Russell, ATC Director, ' and we are well advanced
in building a twin for Gemini South, where we can expect similar exciting
discoveries to come from the southern skies'.

Further images are available from the PPARC website - www.pparc.ac.uk or
from Mark Wells Tel: 01793 442100 Email mark.wells@pparc.ac.uk

1. Gemini South at Sunset
Credit: Gemini Observatory

2. A fish eye view of the Gemini South interior by daylight
Credit: Neelon Crawford

3. GMOS spiral galaxy
Credit: Gemini Observatory - GMOS Team

This image of NGC 628 (M-74) was obtained by the 8.1-metre Gemini North
Telescope on Mauna Kea, Hawaii using the newly commissioned Gemini
Multi-Object Spectrograph. To make the colour image, three images are
combined to make this red, green and blue composite.

Two telescopes, one in each hemisphere, provide access to the whole sky so
that rare events which happen unpredictably anywhere in the sky [for example
black-hole binary systems undergoing outbursts] can be followed with the
northern or southern Gemini telescope.

* Best astronomical sites

The telescopes are sited high up, away from sources of terrestrial light
pollution. The cold, dry, stable air above the Chilean and Hawaiian sites
makes them outstanding locations for astronomy.

* Large light collecting mirrors

The 8.1-metre diameter mirrors provide large surface areas [50 square
metres]. The mirrors are very thin [only 20 centimetres thick], and rely on
a computer controlled support system to maintain their shape.

* Adaptive optics

Blurring of images [star twinkle] caused by the Earth's atmosphere can be
compensated for by correcting in real time using adaptive optics [AO]. In
the Gemini AO system the shape of the mirror is adjusted up to a hundred
times a second to counteract the ripples in the light waves caused by
atmospheric turbulence. This technique is most effective at infrared
wavelengths where it will be a key component in providing sharp images.

The Gemini Observatory provides the astronomical communities in each partner
country with state-of-the-art astronomical facilities that allocate
observing time in proportion to each country's contribution. In addition to
financial support, each country also contributes significant scientific and
technical resources. The national research agencies that form the Gemini
partnership include: the US National Science Foundation (NSF), the UK
Particle Physics and Astronomy Research Council (PPARC), the Canadian
National Research Council (NRC), the Chilean Comision Nacional de
Investigacion Cientifica y Tecnologica (CONICYT), the Australian Research
Council (ARC), the Argentinean Consejo Nacional de
Investigaciones Cientificas y Tecnicas (CONICET) and the Brazilian Conselho
Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq). The Observatory
is managed by the Association of Universities for Research in Astronomy,
Inc. (AURA) under a cooperative agreement with the NSF. The NSF also serves
as the executive agency for the international partnership.

The Particle Physics and Astronomy Research Council (PPARC) is the UK's
strategic science investment agency. It funds research, education and public
understanding in four areas of science - particle physics, astronomy,
cosmology and space science.

PPARC is government funded and provides research grants and studentships to
scientists in British universities, gives researchers access to world-class
facilities and funds the UK membership of international bodies such as the
European Laboratory for Particle Physics (CERN), and the European Space
Agency. It also contributes money for the UK telescopes overseas on La
Palma, Hawaii, Australia and in Chile, the UK Astronomy Technology Centre at
the Royal Observatory, Edinburgh and the MERLIN/VLBI National Facility,
which includes the Lovell Telescope at Jodrell Bank observatory.

PPARC's Public Understanding of Science and Technology Awards Scheme funds
both small local projects and national initiatives aimed at improving public
understanding of its areas of science.